docs: def _verify_any(self):
          """
          Verify that an initial request has been made, or failing that, that
          the request is in the session
          :raises: LTIException
          """
          log.debug('verify_any enter')
  
          # Check to see if there is a new LTI launch request incoming
          newrequest = False
          if flask_request.method == 'POST':
              params = flask_request.form.to_dict()
              initiation = "basic-lti-launch-request"
              if params.get("lti_message_type", None) == initiation:
                  newrequest = True
                  # Scrub the session of the old authentication
                  for prop in LTI_PROPERTY_LIST:
                      if session.get(prop, None):
                          del session[prop]
                  session[LTI_SESSION_KEY] = False
  
          # Attempt the appropriate validation
          # Both of these methods raise LTIException as necessary
          if newrequest:
              self.verify_request()
          else:
              self._verify_session()